Engineering van der Waals Materials for Advanced Metaphotonics.

The outstanding chemical and physical properties of 2D materials, together with their atomically thin nature, make them ideal candidates for metaphotonic device integration and construction, which requires deep subwavelength light-matter interaction to achieve optical functionalities beyond conventional optical phenomena observed in naturally available materials. In addition to their intrinsic properties, the possibility to further manipulate the properties of 2D materials via chemical or physical engineering dramatically enhances their capability, evoking new science on light-matter interaction, leading to leaped performance of existing functional devices and giving birth to new metaphotonic devices that were unattainable previously. Comprehensive understanding of the intrinsic properties of 2D materials, approaches and capabilities for chemical and physical engineering methods, the resulting property modifications and novel functionalities, and applications of metaphotonic devices are provided in this review. Through reviewing the detailed progress in each aspect and the state-of-the-art achievement, insightful analyses of the outstanding challenges and future directions are elucidated in this cross-disciplinary comprehensive review with the aim to provide an overall development picture in the field of 2D material metaphotonics and promote rapid progress in this fast emerging and prosperous field.

An ultrahigh sensitivity micro-cliff graphene wearable pressure sensor made by instant flash light exposure.

Wearable and highly sensitive pressure sensors are of great importance for robotics, health monitoring and biomedical applications. For simultaneously achieving high sensitivity within a broad working range, fast response time (within a few milliseconds), minimal hysteresis and excellent cycling stability are critical for high performance pressure sensors. However, it remains a major challenge. Herein, we report a conceptual micro-cliff design of a graphene sensor with a record high sensitivity of up to 72 568 kPa-1 in a broad working range of 0-255 kPa, which is one order of magnitude higher than the state-of-the-art reported sensitivity. In addition, the detection limit can be as low as 0.35 Pa and the fast response time is less than 5 ms. The sensor also has a minimal hysteresis and an outstanding cycling stability of 5000 cycles, all of which meet the requirements of an ideal pressure sensor. More interestingly, the micro-cliff graphene sensor is made by the fast and scalable flash reduction of graphene oxide using a single flashlight pulse within 150 ms and has been integrated into a wearable smart insole and an E-glove prototype for demonstration of health monitoring applications. This micro-cliff graphene pressure sensor achieves record-high sensitivity, which brings new possibilities in sensor research and promises broad applications.

Study of Hybrid Nanoparticles Modified Epoxy Resin Used in Filament Winding Composite.

Hybrid nanoparticles modified bisphenol A type epoxy/acid anhydride resin system applicable for filament winding forming process was studied using elastic core-shell rubber (CSR) nanoparticles with a large particle size (nearly 100 nm) and rigid nano-SiO2 particles with a small particle size (about 16 nm). The formulation, process properties, mechanical properties, thermal properties and microstructure of modified resin and its wound composite were studied. The results suggested that at the content of 10 phr CSR and 2 phr nano-SiO2, the resin system achieved optimum comprehensive performance. The viscosity of modified resin system was nearly 1000 mPa·s at 25 °C and service life was over 6 h. The resin tensile strength and modulus were 89 MPa and 3.5 GPa, while flexural strength and modulus reached 128 MPa and 3.2 GPa, respectively. The impact strength was 26.6 kJ·m-2, and the glass transition temperature (Tg) reached 145.9 °C. Modified epoxy resin enhanced the mechanical properties of carbon fiber reinforced wound composite. The tensile strength, tensile modulus and interlaminar shear strength were enhanced by 14.0%, 4.56% and 18.9%, respectively, compared with a composite based on unmodified resin. The above test results and scanning electron microscopy (SEM) analysis suggest that the hybrid nanoparticles modified resin system was suitable for carbon fiber wet filament winding products.